maryellen - interesting that you went from 5 part time to 3 full time days.
I went from 5 full days to 5 part-days to 3 full days mostly to suit my training for an AIDS ride. I wanted to be able to ride every morning and then go to work for a few hours (and I should add that I have a short commute).

For the last 2+ years, I've been working Tu-We-Th. If I had a day off in between, I think it would stretch the work week out for me psychologically. And I do think it's easiest to keep it to 3/5 time if you are only in the office 3 days.

Virtually any meeting I attend is internal (I work in local government). I keep my schedule up to date in Outlook and anyone in my agency can see my availability when trying to schedule a meeting (but not what I am doing!). I do check my email and handle things on Mondays and Fridays if I'm home during the day, otherwise not until the evening. Folks at my workplace don't use the phone much, so it's not that noticeable that I'm not physically present on my days off.

PS, I can put in for compensatory time if I want. So when I've needed to put in extra time, I've been willing to do so. It helps that I enjoy my work! I've often been pretty flexible w my schedule but then so has my employer, particularly last year when my father was declining and I had frequent unexpected trips to Florida.

It works well for me and I hope it will for you as well!